The present invention relates to data buffers and, in particular, to devices for exchanging information with a computer when it is halted.
It is known to transmit digital information over bus lines which terminate in receiving and transmitting circuits. These receivers and transmitters typically are integrated circuits designed to restore the signal level which may have become attenuated or noisy over a relatively long cable. Such receivers and transmitters can exchange digital data and can be effectively isolated from its associated bus line by a control signal. It is also known to halt or interrupt a computer so that certain important functions can be performed.
A disadvantage with known systems is their failure to design the buffers into the system to allow gating of data so that it is received at an appropriate time, for example, when the computer is halted. Known systems also fail to consider a buffer system whereby simplex communication can be effected in an orderly fashion.
Accordingly, there is a need for a simple and effective buffer for restoring digitial signal levels while allowing an orderly transfer of data to and from a computer.